Lake Champlain Richelieu River Flood Inundation Mapping and Forecasting Tool

Transcription

1 Lake Champlain Richelieu River Flood Inundation Mapping and Forecasting Tool Rob Flynn USGS New England Water Science Center, NH/VT Office U.S. Department of the Interior U.S. Geological Survey

2 Lake Champlain Richelieu River Study US and Canadian cooperative study under a directive by the International Joint Commission (IJC) IJC study objective is to achieve the best possible flood prediction and inundation mapping for the international, trans-boundary system of Lake Champlain and the Richelieu River Flood Inundation mapping tool will provide emergency managers and residents with information critical for flood-response activities such as evacuations, road closures, disaster declarations, and post-flood recovery.

3 Static Flood Inundation Mapping FY15 Component 2 of IJC directive: creation of a static flood mapping library Production of static flood inundation maps for those communities with LiDAR USGS flood inundation maps to be posted on USGS web site: along with USGS Open File Report Static maps will be produced for 1-ft intervals from 100 to 106 ft (NAVD88) and linked to USGS streamgage (Richelieu River at Rouse s Point NY) and NWS predictions. Static maps will be joined with EC Canada Richelieu River hydrodynamic model output.

4 USGS Flood Inundation Mapper (FIM) website: Flood Inundation Maps translate hydrographs into operational maps that communicate risk

5 Data Needs Real-time stage and streamflow data from a gage Historical flood levels at that gage Current and historical rating curves at that gage Short-term probabilistic forecasts at that gage (NWS) Harmonization of vertical datum Elevation data High-resolution elevation LiDAR data Bathymetry Existing hydraulic model (Richelieu River) Structure data High-water mark data from previous floods

6 Lake level information is currently available at 3 USGS gage locations with 2 more locations to be established in April Additional data will aid in quantifying wind and seiche effects

7 Data Harmonization: US and Canada Datum discrepancy on either side of the US and Canada international border A single vertical datum is needed for US/Canada inundation mapping USGS survey crews will perform GNSS surveys at 3 gages on US side and 4 gages and 2 structures on the Canadian side of Lake Champlain/Richelieu study area to harmonize vertical datum Results of surveying and datum corrections will be presented in a USGS data series report

8 Vertical Datum Discontinuity between Canada and US

9 Survey locations are at 7 benchmarks located at gages and 2 structures GNSS survey requires simultaneous 12-hour observations followed by simultaneous 6-hour observations NAVD88 based on GEOID12A and CGVD2013 based on CGG2013

10 Collection and Processing of LiDAR Data Grande Isle and Franklin Counties (Rock River) LiDAR Flown and Processed (Fall 2014)

11 Addision County LiDAR Flown and Processed (Fall 2014)

12 Chittenden County LiDAR (west) flown and expected to be available in late summer 2015

13 NY side of lake LiDAR to be flown in spring 2015 and processed by late fall of 2015

14 Creation of Flood Inundation Maps Geospatial Processing Create TIN models using cross sections and the modeled water surface profile Intersect the TIN with the DEM to generate predicted inundated areas and depth grids Repeat for all modeled water surface profiles to generate a library of maps

15 USGS FIM Mapper more than just maps Turns the modeled map data into an operational tool by combining data together with tools that enhance the utility and doesn t require any modeling or GIS software or skills Flood Library + USGS Real-time streamgage + NWS Flood Forecast

16 Collection of New Data to Assist with Flood Forecasting and Future Inundation Mapping Component 1 of IJC directive Hydrodynamic 2D model (H2D2) of Lake Champlain and Richelieu River Model will account for wind and seiche effects Install and operate two USGS Lake Water Level and Meteorological Gage Port Henry, NY (15 min lake level and precipitation) Grande Isle, VT (15 min lake level) Three real-time meteorological platforms maintained by UVM through the VT Monitoring Cooperative. Missisquoi Bay Advanced Environmental Monitoring Sensor Array UVM Biogeochemical Station

17 Location of Marine Observational Platforms Three real-time meteorological platforms maintained by UVM through the VT Monitoring Cooperative. Wind, air temperature, dewpoint temperature, water temperature and relative humidity. html/lake/php

18 Missisquoi Bay Advanced Environmental Monitoring Sensor Array UVM Biogeochemical Station Met Station Middlebury Hydrodynamics Vertical Profiler Weekly Depth Grabs ISCO 0.5 m 2m 3m 0.15 m 1m 2m 2.5 m 3m Water depth ~ 3 4m SE portion of bay insulated from S, E, W winds Site of the most intense BGA blooms 2012 present continuous data (Spring Fall)

19 Questions Robert Flynn USGS New England Water Science Center, NH/VT Office